Connection for running incandescent lamps and arc-lamps in common.



W. SGHAPPER.

CONNECTION FOR RUNNING INGANDESGENT LAMPS AND ARC LAMPS IN GOMMON.

' APPLICATION FILED JAN. 13, 1910.

1,033,275. Patentd July 23, 1912.

WALTER SCI-IAFFE'R, OF BERLIN, GERMANY.

CONNECTION FOE RUNNING INCANDESCENT LAMPS AND ARC-LAMPS IN COMMON.

Application filed January 13, 1910.

, Specification of Letters Patent.

Patented July 23, 191.2.

Serial No. 537,822.

T 0 all whom it may cancer-21.:

Be it known that l, lihmrnn Sculiri-an, engineer, a subject of the Emperor oi Germany. residing at Geisbergstrasse Ben lin, Germany, have invented certain new and useful Improvements in or Relating to Connections for Running Incandescent Lamps and Arc-Lan'ips in Common, of which the following is a specification.

My invention relates to connections for running incandescent lamps and are lamps inconunon in alternate current systems employing an auto transformer.

According to my invention I connect groups of incandescent. lamps and groups of are lamps with the auto transformer by sub- 'stituting the series resistance of the groups.

of arc lamps by the group of incandescent lamps, both gIOUpS being connected in series to the terminals ot' the transformer. From one point of the auto transformer, however, which subdivides the total. tension in the ratio of the tensions atthe terminals of the groups of incandescent lamps and are lamps, I lead a. branch line to a point of the line connecting the group of incandescent lamps with the group of are lamps. This mode of connection is based on the tollowing cmisidcrations: .ln each incandescent lamp circuit. the current has of course to be kept as constant as possible, because when the current varies, apart from the possibility of injuring the lamps, changes in their luminous intensity are caused. But if I incandescent lamps are connected in series with are lamps and. are to serve as their series resistance, this requirement of avoiding fluctuation of current is opposed by the arc lamps requiring regularly recurring rariation of current and poteiitial, because regulation is effected precisely. by these changes. In a circuit in which are lamps and incandescent lamps are connected in series use therefore. gannot be made of the well-known means for keeping constant the strength of current.

ished by the amount of these COlllPQllSt ting currents. As described hereinafter, 1 can indeed, entirely prevent the occurrence of these fluctuations of current. Consequently my connection enables the employment of incandescent lamps 'as series resistance for alternate current are lamps in the most favorable manner.

Two illustrative embodiments of my invention are represented diagrammatically and by way of example in the accompanying drawing, wherein Figure 1 shows one arrangement, and Fig. 2 shows a modified arrangement.

Referring to the drawing, 1 and 2 are the terminals of analternating current system. connected with the terminals 3 and 4 of an auto transformer. The group 5 of incandescent lamps and the group of are lamps 6 are connected in series between the terminalsB and 4, the incandescent lamps formmg the-series resistance for the are lamps.

-In order to enable this without the tension at the terminals of the group of incandescent lamps varying noticeably when changes in current occur, I connect a branch line 9 between a point 7 of the auto transformer and. a point 8 of the lamp line. This branch without current in the normal condition of the plant. But when the resistance of the arc lamps varies, a portion of the requisite compensation current flows through the branch, and the tension at the terminals of the group of incandescent lamps accordingly is varied considerably less than pro portionally to the variation of the are lamp current.

The internal resistance of the transformer coils must be proportioned corresponding to the'variation of tension of the are lamps necessary for their regulation, which variation of course must. and indeed can be admissible for the group of incandescent lamps.

if itis wished not to subject the incandescent lamps to these fluctnations oi tension, they can be negatu'ed by mterpohuimg in series a regulating resistance 10, e.

resistance of the Well-known type of iron resistances. Obviously, the fluctuations of cur rent will then be keptfrom the incandescent lamps and the conditions are favorable in every respect.

Under certain circumstances it may happen that the resistanceof the are lamps 6, 6 becomes exceedingly smalh'zspecially if .the carbons of both the arc lamps strike together simultaneously. The portion of the auto transformer located between the points 7 and 4 would then, however, becomenlmost current-less and that might cause an inad missible rise of tension in the incandescent lamp circuit. To remedy this drawback with certainty, as illustrated in Fig. 2 I may insert in the arc' lamp circuit, between the points 8 and 4:, one or more regulating re .sistances 11 which are proportioned for a greater working current than the normal maximum currentof the arc lamps. For

example, if the arc lamps are meant for 10 amperes I adjust the regulating resistance 11 to approximately 12 amperes working current. Then so long as the current is about 10 amperes or less the regulating resistance varies the resistance in the arc lamp circuit only very slightly but increases it exceedingly as soon as the current exceeds '10 amperes, say, so that 12 amperes cannot be exceeded. In this manner coils 7 i are prevented from becoming current-less and consequently inadmissible rise of tension at the incandescent lamp terminals is also prevented.

I claim 1. In an alternating current electric lighting system, the combination with an autotransformer, of a group of incandescent lamps and a group of arc lamps connected in series between the terminals of said transformer, a branch line having one end con neeted between said groups and the other end to a point of said transformer which divides the total tension thereof in the ratio of the terminal tensions of said groups, and a resistance regulator placed in series with said group of incandescent lamps and located between the terminal of the transformer to which this group is connected and the other end of said branchline.

2. In an alternating current electric lighting system, the combination with an autotransiormer, of a group of incandescent lamps and a group of are lamps connected in series between the terminals of said transformer, a branch line having one end connected between said groups and the other end to a point of said transformer which divides the total tension thereof in the ratio of the terminal tensions oi said groups, a resistance regulator placed in. series with said group of incandescent lamps and located between the terminals of the transformer to which this group is connected and the other end of said branch, and a resistance regulator connected in series with said group of arc lamps, said. resistance regulators being adjusted for a somewhat greater working current than the normal current of the are lamps.

8. In an alternating current electric lighting system, the combination with an autotransformer, of a group of incandescent lamps and a group of are lamps connected in series between the terminals of said transformer, a branch line having one end connected between said groups and the other end to a point of said transtorn'ier which divides the total tension thereof in the ratio of the terminal tensions of said groups, and one or more resistance regulators connected in series with said group of are lamps, said re sistance regulators being adjusted for a.

somewhat greater working current than the normal current of the are lamps.

In testimony whereof I have signed my name to this specification 1n the presence of two witnesses.

T wmrrnr. sonltrrnn.

litnesses WoLnmrAn Haerr, HENRY I'IASPER. 

